import java.util.Stack;

public class MyQueueUseStack {
    Stack<Integer>stack1;
    Stack<Integer>stack2;
    public MyQueueUseStack() {
        stack1=new Stack<>();
        stack2=new Stack<>();
    }

    public void push(int x) {
        stack1.push(x);

    }

    public int pop() {
        if(empty()){
            return -1;
        }
        if(stack2.empty()){
            int size= stack1.size();
            for (int i = 0; i <size ; i++) {
                int val=stack1.pop();
                stack2.push(val);
            }
            return stack2.pop();
        }else {
            return stack2.pop();
        }

    }

    public int peek() {
        if(empty()){
            return -1;
        }
        if(stack2.empty()){
            int size= stack1.size();
            for (int i = 0; i <size ; i++) {
                int val=stack1.pop();
                stack2.push(val);
            }
            return stack2.peek();
        }else {
            return stack2.peek();
        }

    }

    public boolean empty() {
        return stack1.empty()&&stack2.empty();

    }
}
